In Season 2, The Flash has been so weighted with serialized drama that it can be easy to forget its more simplistic beginnings. Sure, the show still does the occasional Metahuman of the Week storyline, presenting Barry (Grant Gustin) and the team with a problem to solve. But those sorts of stories are generally situated in a broader narrative context. Even last week’s “Trajectory” tied the titular villain into overarching hunt for Zoom, as it was Trajectory’s reaction to Veloctiy-9 that gave Barry the clues he neded to figure out Zoom’s true identity. But “Flash Back” is a thrilling blast from the past, as we get a story that, while embedded within the serialization of the show as a whole, tells a story that brings out nostalgia for the more lighthearted version of The Flash from Season 1.

Of course, calling Season 1 “lighthearted” undersells just how dark it occasionally got, between the reveal about Wells (Tom Cavanagh) being a traitor and Barry trying to exonerate his father for the murder of his mother. But the series felt more adventurous then, even while I think Season 2 has been a far stronger season overall. So “Flash Back” was a welcome change of pace, as Barry goes back in time to seek aid from Eobard Thawne in order to be fast enough to stop Zoom. It’s an interesting storyline for a variety of reasons. First and foremost, it allows Cavanagh to dig back into the Thawne persona. While he had the better part of last season to play a villain, it still didn’t feel like nearly enough. So this was a treat, particularly since he’s not exactly a stupid villain either. He’s quick to recognize that this isn’t his Barry Allen, and he’s able to deduce from what Barry knows, and which powers he’s acquired, just how successful his plan to get back home to his timeline is going to end up being. But to Barry’s credit, he succeeds in convincing Thawne that he’s actually successful in getting back home, creating a cover story in which Thawne’s return trip home creates a singularity that needs to be dealt with — a lie that, technically, isn’t a lie at all. It’s just that the singularity isn’t the problem Barry is trying to solve right now. Seeing Barry square off with Thawne on more equal footing is a joy to watch, and it creates a compelling conflict around which to arc the episode, since Barry desperately needs Thawne’s help, and Thawne can’t afford not to help Barry since this Barry is blackmailing him: if he should come to any harm, then Thawne’s Barry will receive a letter detailing exactly how to foil Thawne’s accelerator plan. Thawne can’t tell if Barry is bluffing or not, but it doesn’t really seem to matter if he’s telling the truth or not, since the doubt is already there in Thawne’s mind. As a result, we get Barry and Thawne working together again, for old times’ sake.

Credit: The CW

Surprisingly, the least interesting aspect of this week’s story is its Supernatural Threat of the Week, in this case a “time wraith” hunting down Barry to correct this apparent time anomaly. It’s not that the creature itself isn’t awesome (looking like a terrifying cross between a mutant and a Dementor from Harry Potter), but rather than it feels kind of shoehorned in. The story of Barry trying to get Wells to help him solve the Speed Force formula would have been a perfectly serviceable plot on its own without introducing an external threat that needs to be taken care of. However, I will say that it at least results in the week’s most pleasant surprise, which is that Pied Piper/Hartley Rathaway (Andy Mientus) has been reformed, and opts to help Cisco (Carlos Valdes) and Caitlin (Danielle Panabaker) figure out how to stop the ghoul in the future. In fact, Hartley is the one who saves Barry when Cisco’s anti-wraith weapon doesn’t work, as his old Pied Piper gloves do the trick once they’re tuned to a new frequency and output. It might seem like it’s all coming a bit out of left field, but I think it’s important to show that Barry isn’t simply fighting to end crime and wipe out all the criminals and threats in Central City. We need to see that bad guys can be reformed. While this isn’t a bleak and repressive universe, it can occasionally lack a sense of hope for the weekly villains. Sure, Earth-2 Wells is proving himself to be a fairly stand-up guy (albeit within the context of protecting his daughter), but it helps give the sense that Barry and his team are doing more than just putting an end to crime — they’re helping reform the criminals themselves. It’s great stuff, and Mientus could be an asset to the cast, just as much as Hartley could be an asset to the STAR Labs team.

Credit: The CW

Barry’s sojourn into the past results in some cool moments, naturally. In addition to Wells finally giving Barry the Speed Force solution that will allow him to become fast enough to face Zoom, we get a neat confrontation in which future Barry meets past Barry and the STAR Labs team, leading to a hilarious standoff in which Cisco struggles to rap his head around what’s happening in front of him. It’s that lighthearted, comedic quality in the face of impending doom that helps give this that Season 1 feeling, and it all culminates in a pretty great finale, in which past Barry helps future Barry get through the rift back to his own time before the Time Wraith can catch him. Granted, the Time Wraith still manages to go through the portal as well, but Hartley deals with the creature on the other side. It’s a cool sequence, and it’s part of a storyline that also sees Barry closing some loose ends with past versions of people he knows. Earlier in the episode, he approaches Eddie (Rick Cosnett) and gets him to record a message to Iris (Candice Patton) that will help give her the strength to move on from his death. Granted, Barry records the video under the guise of creating a birthday video for Iris with comments from her loved ones. But it works all the same, giving Iris the strength to perhaps get past the trauma of having lost Eddie in the first place. I’m not always riveted by stories having to do with Iris, but I thought this was pretty poignant stuff, and it helped bring the episode full circle, as we end on two people dealing with their pasts while looking ahead to their respective future. In Barry’s case, that means taking down Zoom — and, once again, squaring off against a mentor he thought was a friend. I guess Barry’s conflicts are cyclical, no?

“Flash Back” is a thrilling episode that’s a lot of fun, bringing back a feeling of nostalgia for the simpler, more straightforward first season. I’m still loving the complexity of Season 2, with the multiple universes and less obsessive focus on romantic entanglements (well, recently, at least). But this was a nice change of pace for The Flash, just the same.

But what did you think of The Flash Season 2 Episode 17, “Flash Back”? Sound off in the comments!